Family, fertility and economics are inextricably intertwined. Yet despite intensive investigation, the interdependencies among these phenomena remain elusive. The difficulties encountered by conventional theory stem from fundamental conceptual errors: questionable assumptions about the nature of the data and problem, the use of overly general constructs, and the use of perspectives too narrow to address the necessary issues. A natural selection perspective on familial patterns resolves these conceptual problems. This project intends to clarify interdependencies among family, fertility and economics by the application of this perspective. This project posits that familial patterns (family structure and fertility) emerge in adaptation to economic constraints and options established by technology. The line of reasoning stemming from this proposition leads to conclusions about familial patterns that are consistent with the complexity of family patterns documented for Africa and throughout the industrial and industrializing world. These conclusions also point to differences in familial patterns in Africa that have not been explored. Preliminary application of this approach has provided a parsimonious, powerful explanation for variations in family and fertility among the Bassa of Liberia. These results indicate that further work with this framework should prove most profitable. This project extends earlier work to examine in detail possible differences in familial pattern among cash crop farmers, subsistence farmers, entrepreneurs, highly educated managers and professionals, white collar workers and skilled laborers, and illiterate, unskilled laborers. The project develops a numerical methodology combining informal observation and interviews with survey data, and factor and path analysis to test these and other possibilities, and to provide a firm ground for replicative studies in the future.